T-carrier communication systems are well known and are in common use by telephone companies for voice or data transmission. Such systems employ pulse coded modulation to transmit digitized voice or data signals. Telephone companies presently are offering one or more types of digital service including 1.544 Mega-bit per second T1 digital service and 3.1520 Mega-bit per second T1C digital service.
Because of the high frequency involved, the carrier signal (pulse train) attenuates rapidly. For example, the T1 signal typically can only be transmitted a maximum of approximately 6,000 feet before having to be regenerated by a line repeater. Accordingly, a telephone company may need one or more line repeaters between its central office and the customer location to maintain a desired level of the carrier signal.
Heretofore, apparatus cases were used to house the line repeaters. These cases could house a plurality of line repeaters for multiple T1 lines. The apparatus cases were water-tight and provided needed protection for the line repeaters when located in manholes where the cases often were under water. To facilitate in-line connection of the repeaters, repeater connectors in the cases were wired with cable stubs that extended outside the case for splicing into the T1 lines.
However, from time to time, there would be a need to install one or just a few line repeaters at a particular location, such as at the customer site. Heretofore, it was a common practice to install the line repeater or repeaters in an apparatus case at substantial cost for both the case and installation. Moreover, the relatively large and bulky apparatus case took considerable space in oftentimes cramped or confined areas.